JP3531360B2 - Cold rolling method for sheet material with work roll shift during rolling - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cold rolling method in which a work wheel is axially shifted during rolling, and more particularly to a cold rolling method in which plate thickness does not fluctuate during work rolling. .

[0002]

2. Description of the Related Art When a plate material is rolled by a continuous rolling mill, it has been conventionally practiced to shift the work wheel axially in order to reduce an edge drop that occurs at the end of the plate. ing. This work roll shift is not only performed for the purpose of reducing the edge drop, but is formed by the contact of the corner portion of the plate end with the work roll. It is also used for the purpose of preventing the edge mark of the crawl and controlling the shape in the plate width direction.

In particular, when the work wheel shift is applied for the purpose of reducing the edge drop, one end of the work wheel is disclosed in, for example, Japanese Patent Publication No. 60-52121. A method such as processing the shape of the portion into a taper shape is adopted.

When the rolling by the work roll shift is applied to the cold rolling, the cold rolling is generally a complete continuous rolling in which a plurality of original plate coils (coils before cold rolling) are welded and connected one after another. Therefore, it is necessary to perform a work roll shift during rolling mainly depending on the plate width of the original coil to be rolled.

However, if the work wheel shift is performed during rolling, a problem as disclosed in JP-A-7-100502 occurs. That is, during the work wheel shift, the plate material has grinding marks formed on the surface of the work wheel in a direction orthogonal to the axial direction (feed of the grinding wheel during roll grinding). Associated with
The friction coefficient increases, and the plate thickness of the original coil rolled during the work roll shift increases. Is.

In order to prevent such behavior, in Japanese Patent Laid-Open No. 7-100502, the work speed is set at a shift speed determined by using at least one of the rolling speed and the surface roughness of the work wheel as a control factor. A method of rolling while shifting the chrome is disclosed.

Regarding the increase in the coefficient of friction that causes such an increase in strip thickness, a similar report has been made in the rolling method in which the upper and lower rolls are crossed (October 1992,
The 43rd Joint Symposium on Plastic Working, Proceedings II, "Load characteristics of cold-rolled thin sheet").

Such a phenomenon in the cross roll rolling is the same as the case where the work roll is shifted during rolling in that the rolled material is skewed with respect to the grinding marks on the surface of the work roll. is there.

[0009]

However, the above-mentioned conventional technique has the following problems.

That is, the present inventors applied the BISRA-AGC (BISRA type plate thickness control device) to the stand for performing the work roll shift when shifting the work roll during rolling. When the control was performed, it was examined how the plate thickness on the stand-out side where the work wheel shift is performed and the plate thickness on the downstream side of the stand change.

FIG. 9 shows a 5-stand continuous cold rolling mill to which BISRA-AGC is applied as an automatic plate thickness control means in the first stand. During cold rolling of a plate material at a rolling speed of 45 m / min, It is a graph which shows the time-dependent rolling load and the fluctuation | variation of the plate thickness of a rolling material at the time of shifting the 1st stand work wheel whose surface roughness Ra is 1 micrometer at a shift speed of 2 mm / min. , (A) shows the change in the distance between the center of the body of the upper and lower work wheels and the center of the pass line (called the work wheel shift position) of the first stand for performing the work wheel shift, and (b) shows The fluctuation of the rolling load in the first stand, (c) the change in plate thickness on the outlet side of the first stand, (d) the change in plate thickness on the outlet side of the second stand,
(E) is a graph showing the change of the plate thickness on the exit side of the fifth stand, which is the final stand.

As can be seen from FIG. 9 (b), in the first stand where the work wheel shift is performed during rolling, the work is
The rolling load increases only during the chrome shift.

BISRA-AGC can prevent an increase in plate thickness due to such an increase in rolling load, and as shown in FIG. 9 (c), the plate thickness at the delivery side of the first stand is substantially constant. The thickness is controlled.

However, even if the plate thickness is kept constant in the first stand for performing the work wheel shift,
The next second stand outlet side plate thickness decreases as shown in FIG. 9 (d) while the first stand undergoes the work wheel shift, and due to the influence, the output of the fifth stand which is the final stand. As shown in FIG. 9E, the finished plate thickness on the side is also smaller than the target plate thickness by several μm to several tens μm.

The technique disclosed in Japanese Patent Application Laid-Open No. 7-100502 is for keeping the outgoing side plate thickness of the stand performing the work wheel shift constant, and as described above, the finishing plate thickness. There is a problem that cannot be held constant.

It should be noted that the Japanese Patent Publication No. 60-51921 does not disclose a measure for plate thickness variation when performing a work wheel shift during rolling.

The present invention has been made in order to solve the above-mentioned problems of the prior art, and an object thereof is to prevent the variation of the finish plate thickness when performing work roll shift during rolling. .

[0018]

SUMMARY OF THE INVENTION A first cold rolling method of a plate material for performing a work wheel shift during rolling according to the present invention is one in which the work wheels arranged vertically are respectively Using a continuous cold rolling mill equipped with an axially shiftable stand and tension control means for controlling the exit side tension of the shifting stand by changing the roll gap of the next stand. In the cold rolling method of the plate material in which the work roll shift is performed, the band width of the tension control means for controlling the exit side tension of the shifted stand is set to the work roll during the period from the start to the end of the work roll shift. -Rolling is performed with a width larger than the band width during steady rolling without rolling shift.

Further, during the second rolling according to the present invention, the work is performed.
The cold rolling method of the plate material for performing the croll shift is such that the work rolls arranged vertically opposite to each other can be shifted in the respective axial directions, and the output side tension of the stand to be shifted can be adjusted to the next stand. A continuous cold rolling mill equipped with a tension control means for controlling the roll gap by changing the roll gap is used to start a work roll shift in a cold rolling method for a plate material in which work rolls are shifted during rolling. During the period from the end to the end, the target value of the tension control of the tension control means for controlling the exit side tension of the shifted stand is set higher than that in the steady rolling in which the work wheel shift is not performed.

In addition, during the third rolling according to the present invention, the work is performed.
The method of cold rolling a plate material that performs a crow shift is a stand that can shift the work wheels arranged vertically opposite each other in each axial direction, and the output side tension of this stand to the roll of the next stand. In a cold rolling method for a plate material, in which a work roll is shifted during rolling using a continuous cold rolling mill equipped with a tension control means for controlling by changing the roll gap, the exit side of a shiftable stand The tension control is not performed from the start to the end of the work roll shift by keeping the roll gap of the next stand constant, and is controlled by the roll gap control means during steady rolling without performing work roll shift. It is to be rolled.

In addition, during the fourth rolling according to the present invention, the work is performed.
The cold rolling method of the plate material for performing the croll shift is such that the work rolls arranged vertically opposite to each other can be shifted in the respective axial directions, and the output side tension of the stand to be shifted can be adjusted to the next stand. During the rolling, a continuous cold rolling mill equipped with a tension control means for controlling by changing the roll gap and a BISRA type plate thickness control means for controlling the roll gap in the shiftable stand is used. In the cold rolling method for a plate material in which work rolls are shifted to, the control of the output side tension of the shifted stand is performed by adjusting the roll gap of the shifted stand from the start to the end of the work roll shift by the BISRA type plate. It is performed by controlling with the thickness control means, and during steady rolling without work roll shift, rolling is performed while performing with the tension control means. That.

In addition, during the fifth rolling according to the present invention, the work is performed.
The cold rolling method of the plate material for performing the croll shift is a tensiometer in which the work wheels arranged to face each other vertically are shiftable in their respective axial directions and the stand on the exit side of the shifted stand. In a cold rolling method of a plate material in which a work roll is shifted during rolling using a continuous cold rolling mill equipped with and, control of the exit side tension of the shifted stand is completed from the start of the work roll shift. Up to the above, the rotation speed of the shifted work roll is changed, and during steady rolling without the work roll shift, the roll gap of the next stand is determined based on the tension signal from the tensiometer. The rolling is performed while changing the value.

The inventor of the present invention has made a detailed analysis of the cause of the plate thickness variation when performing work roll shift during rolling, and has found that the following mechanism is an essential cause. . That is, when performing work roll shift during rolling, the rolling material is skewed with respect to the grinding marks on the roll surface, changes occur in the lubrication state in the roll bite, and not only the average value of the friction coefficient, It was concluded that the change in the distribution causes the neutral point to move in the direction toward the roll bite exit side, which increases the inter-stand tension in front of the stand and causes the plate thickness fluctuation. .

Generally, the lubrication condition in the roll bite during cold rolling is such that the lubricating oil film introduced at the bite inlet becomes thinner as the material stretches in the rolling direction and the contact between the roll and the rolled material. The department is expanding. Therefore, it is considered that fluid lubrication was dominant at the roll bite inlet, but the boundary lubrication region expanded toward the roll bite outlet, and the rolling material slanted with respect to the grinding grain of the rolling roll. It is thought that the impact of doing this will be closer to the exit of the roll bite, that is, will have a greater impact in the advanced region.

FIG. 10 shows (a) when the work wheel shift is performed under the same conditions and timings as those described with reference to FIG. FIG. 4B is a graph showing changes over time in tension between the first and second stands (tension between front stands), and (c) is a change over time in tension on the entrance side of the first stand (rear tension). . As described in FIG. 9, BISRA-
It is confirmed that the advance ratio is lowered during the shift as shown in FIG. 10A, although the plate thickness on the exit side of the shift stand is kept constant by the AGC. Further, as shown in FIG. 10C, the tension between the front stands is increased by about 10% as shown in FIG. 10B, although the rear tension is controlled to be substantially constant. I understand. It is a well known fact that the increase in the tension between the front stands greatly affects the exit side plate thickness of the front stand (second stand), and it is possible that the front stand exit side plate thickness is reduced by this. , It was concluded that it is a mechanism of plate thickness fluctuation when performing work roll shift.

That is, the plate thickness variation that occurs when the work roll is shifted during rolling is essentially the movement of the neutral point in the roll bite exit direction due to the change in the lubrication state.
This is the increase in tension between the front stands, which results in BISR
Even if the output side plate thickness in the shift stand is kept constant by means such as A-AGC.

Therefore, in order to reduce the variation in the finish plate thickness, it is necessary to reduce the tension in front of the shift stand.

A commonly used tension control method called TLC (TLC, tension limit control)
Is the abbreviation of the stand, and controls the tension by changing the roll gap of the next stand.) If the tension between the stands deviates from the target value, operate the hydraulic pressure reduction of the downstream stand to It tries to bring the tension close to the target value. For example, when the tension between the first and second stands is higher than the target value, the roll gap in the second stand is reduced to increase the reduction rate, and thereby the material inflow velocity on the second stand entry side. Is controlled to reduce the tension between the first and second stands.

When the tension control by TLC is applied to the case of performing the work wheel shift during rolling, the following problems occur. That is, when the work roll shift is performed in the first stand, the tension between the first and second stands is increased due to the change of the rolling state in the first stand, which reduces the delivery side plate thickness of the second stand. Since this is the cause of the plate thickness fluctuation, when the tension control by the TLC is used, the plate thickness in the second stand is further reduced, which has an adverse effect.

As described above, since the conventional tension control promotes the plate thickness fluctuation that occurs when the work roll is shifted, the present invention prevents the plate thickness fluctuation from being promoted by the following method. The thickness variation was reduced to a level where there was no practical problem.

The above-mentioned tension control (TLC) which is commonly used
In (1), a certain band width is set with respect to the target value of the tension, and when the tension exceeds the band width, the rolling operation of the next stand is performed. Usually, for the purpose of controlling tension with high precision, a standard value of tension of ± 5% is set as the band width. Therefore, in the cold rolling method for the plate material which performs the work roll shift during the first rolling according to the present invention, from the start to the end of the work roll shift,
The band width was made wider than usual, and even if the front tension fluctuated due to the work roll shift, the rolling operation at the next stand was not performed. As a result, it is possible to prevent the TLC from promoting the variation of the plate thickness during the work roll shift. In particular, since the tension in front of the shift stand increases with the shift, a sufficient effect can be obtained by expanding the positive side of the band width.

Further, in the tension control by the normal rolling operation, it is an effective means to increase the target value of the inter-stand tension control between the shift stand and the next stand only when the work roll is shifted. This is to prevent the reduction operation by TLC from being performed when an increase in the forward tension due to the shift occurs, as in the case of increasing the band width, and the reduction operation promotes the variation in plate thickness. It has the effect of preventing.

Therefore, in the cold rolling method for the plate material in which the work roll shift is performed during the second rolling according to the present invention, the target value of the inter-stand tension control is increased only during the work roll shift. I did it.

The forward movement of the neutral point during the work roll shift is caused by the change in the lubrication state, and the rolling speed, the shift speed, the roll roughness and the viscosity of the rolling oil are the main influencing factors. is there. Such a movement of the neutral point, that is, a change in the advanced rate, becomes larger as the rolling speed becomes lower and the shift speed becomes faster, and becomes larger as the roll roughness becomes rough. There is a large correlation with the quantity. Therefore, by investigating the relationship between the amount of change in tension due to such shift, the rolling speed, the shift speed, and the roll roughness, it is possible to change the appropriate target tension value according to the operating conditions.

Further, it is an effective means that the control by TLC is not performed from the start to the end of the work roll shift. In this case, of course, it is possible to prevent the phenomenon in which the TLC promotes the plate thickness variation during the work roll shift. However, during that period, as a rolling operation, switching to roll gap position control (keeping the roll gap constant) is performed, as in the cold rolling method for plate materials that performs work roll shifting during the third rolling according to the present invention. Alternatively, as in the cold rolling method for a plate material in which the work roll shift is performed during the fourth rolling according to the present invention, BISRA-AG
It is necessary to perform the rolling-down control using C. In particular, BISR
When used in combination with A-AGC, it is a more effective means because it can prevent the plate thickness variation in the shift stand.

Further, the normal tension control is performed by operating the reduction of the next stand by utilizing the high responsiveness of the hydraulic pressure reduction. However, the work of the shift stand is performed only during the work roll shift during rolling. It is also possible to control the tension by changing the rotation speed of the crawl. For example, when the work roll shift is performed on the first stand, the forward tension (tension between the first and second stands) increases, so tension control is performed by changing the rotation speed of the work roll of the shift stand. By carrying out, that is, by reducing the rotation speed of the work roll of the first stand, it is possible to prevent tension fluctuation between the first and second stands. By the way, in the tension control in normal cold rolling, such a method can not be taken is that the response of the roll speed change is low compared to the response under hydraulic pressure, and it is possible to perform tension control with high response. Because it is not possible,
As long as this method is adopted only during the chrome shift, the responsiveness does not matter.

Therefore, in the fifth cold rolling method of the plate material for performing the work roll shift during rolling according to the present invention, the rotation speed of the work roll is changed only during the work roll shifting. While the tension control is performed and the work wheel shift is not performed, the roll gap of the next stand is changed based on the tension signal from the tensiometer to reduce the plate thickness variation during the work wheel shift. I tried to prevent it.

Incidentally, the technique of controlling the tension is generally used for the purpose of preventing the plate thickness variation in the tandem rolling, but the work roll shift operation originally used for the purpose of controlling the profile in the plate width direction is performed. Correspondingly,
In order to prevent the plate thickness fluctuation that occurs as a disturbance,
Until now, there has been no method to change the tension control parameters or control method from the start to the end of the work roll shift.

[0039]

BEST MODE FOR CARRYING OUT THE INVENTION A cold rolling method for a plate material, which performs a work roll shift during rolling according to a first embodiment of the present invention,
This will be described with reference to FIG.

FIG. 1 is a control system diagram for explaining a cold rolling method for a plate material in which a work wheel shift is performed during rolling in this embodiment. First acting on plate 1 during rolling
The tension between the stand 2 and the second stand 3 is detected by the tensiometer 4 provided between the first and second stands, and the tension signal is TL.
It is input to the tension control device 5 by C. In the tension control device 5, the input tension signal is compared with the preset upper and lower limits of the target value for tension control, and the detected tension is outside the upper and lower limits of the target value. At this time, a command is issued to the hydraulic pressure reducing device 6 of the second stand 3, and the hydraulic pressure reducing device 6 changes the roll gap between the upper and lower work wheels 3a of the second stand 3.

That is, when the detected tension exceeds the upper limit of the target value, the roll gap is manipulated to be smaller. As a result, the rolling reduction increases and the inflow speed of the material on the inlet side of the second stand 3 decreases, so that the tension between the first stand 2 and the second stand 3 decreases.

When the detected tension is below the lower limit of the target value, the roll gap is increased. As a result, the rolling reduction is reduced and the inflow speed of the material on the inlet side of the second stand 3 is increased, so that the tension between the first stand 2 and the second stand 3 is increased.

The work roll 2 of the first stand 2
a is controlled by the work wheel shift control device 7 during rolling.
When shifting in the axial direction, a work roll shift start signal is sent from the work roll shift control device 7 to the tension control device 5. In the tension control device 5, the upper limit of the target value of the tension control is changed to a larger value and the lower limit of the target value is changed to a smaller value from the time when the work wheel shift start signal is received. This change continues until the signal for finishing the work wheel shift is input from the work wheel shift control device 7, and after the work wheel shift is completed, the original upper limit value and the lower limit value are restored.

The graph of FIG. 2 shows that the upper and lower limits (upper limit and lower limit) of the target value of the tension control are obtained during the steady rolling in which the work roll shift is performed in the first stand and the work roll shift is not performed during rolling. (The width between the lower limits is called the bandwidth) is set to ± 5% of the standard value, while the band width is -5% of the standard value from the start to the end of the work roll shift. Shows the variation with time of the plate thickness and the tension when changing from + 30% to + 30%. (A) shows the upper and lower work wheels of the first stand for the work wheel shift. The shift position, (b) the band width in tension control, (c) the thickness deviation on the delivery side of the first stand,
(D) shows the thickness deviation on the delivery side of the second stand, (e)
Shows the plate thickness deviation on the exit side of the fifth stand, which is the final stand, and (f) shows the change in tension between the first and second stands. As shown in FIG. 2 (f), although the tension fluctuation between the first and second stands is not small as compared with the conventional method, the decrease in the second stand outlet side plate thickness is
It is suppressed as shown in FIG. 2D, and the plate thickness variation in the final stand is also reduced to a level at which there is no practical problem as shown in FIG. 2E.

Next, referring to FIG. 3, a method of cold rolling a plate material in which the work wheel shift is performed during rolling according to the second embodiment of the present invention will be described.

FIG. 3 shows a plate material cold rolling method according to a second embodiment of the present invention, in which a work roll shift is performed during rolling.
It is a control system diagram for explaining. In FIG. 3, FIG.
The same components as those described in 1 are assigned the same reference numerals as those in FIG.
Detailed description thereof will be omitted. In the cold rolling method of the plate material in which the work roll shift is performed during the rolling of the present embodiment, the first method is the same as that described with reference to FIG. 1 during the steady rolling in which the work roll shift is not performed during the rolling. -Tension control between the two stands is performed. Then, when the work wheel 2a of the first stand 2 is axially shifted by the work wheel shift control device 7 during rolling, the work wheel shift control device 7 causes the work wheel roll 2a to shift. The le-shift start signal is sent to the tension control device 5. In the tension control device 5, the tension control target value is increased from the time when the work wheel shift start signal is received until the time when the work wheel shift end signal is received to increase the target value between the first and second stands. Tension control is performed.

After the end of the work wheel shift, the target value of the tension control is returned to the original value and the tension control is performed.

The target value of the tension control during the shift differs depending on the shift speed, rolling speed, roll roughness, and the viscosity and concentration of the rolling oil. The optimum target value is calculated by and is input to the tension control device 5.

FIG. 4 shows the setting of the target value for tension control when performing the work roll shift during rolling when the work roll shift is performed at the first stand. It shows the variation with time of the plate thickness and tension when the rolling speed is increased by 10% compared to the case of no steady rolling.
(A) is the change position of the upper and lower work rolls of the first stand for performing the work roll shift, and (b) is the change of the target value based on the target value of the tension control during steady rolling. Quantity, (c) is the thickness deviation on the outlet side of the first stand,
(D) shows the thickness deviation on the delivery side of the second stand, (e)
Shows the plate thickness deviation on the exit side of the fifth stand, which is the final stand, and (f) shows the change in tension between the first and second stands. As shown in FIG. 4 (f), although it is not possible to reduce the tension fluctuation between the first and second stands as compared with the conventional method, the decrease in the second stand outlet side plate thickness is as shown in FIG. 4 (d). As shown in FIG. 4 (e), the plate thickness variation in the final stand is also suppressed as shown in FIG.
It has been reduced to a level where there is no practical problem.

Next, a third embodiment of the present invention will be described with reference to FIG. 5, which is a method of cold rolling a plate material for performing work roll shifting during rolling.

FIG. 5 shows a cold rolling method for a plate material in which a work wheel shift is performed during rolling according to a third embodiment of the present invention.
It is a control system diagram for explaining. In FIG. 5, FIG.
The same components as those described in FIG. 3 and FIG. 3 are assigned the same reference numerals as those in FIGS. 1 and 3 and detailed description thereof will be omitted. The cold rolling method of the plate material in which the work roll shift is performed during the rolling of this embodiment is the same as that described in FIG. 1 and FIG. 3 during the steady rolling in which the work roll shift is not performed during the rolling. Then, tension control between the first and second stands is performed. Then, when the work wheel 2a of the first stand 2 is axially shifted by the work wheel shift control device 7 during rolling, the work wheel shift control device 7 causes the work wheel roll 2a to shift. The le shift start signal is sent to the tension control device 5 and the rolling position control device 8. In the tension control device 5, the control command to the hydraulic pressure lowering device 6 of the second stand is stopped until the work wheel shift end signal is sent from the work wheel shift control device 7. At the same time, the rolling position control device 8 controls the hydraulic rolling down device 6 so that the roll rolling position (roll gap) of the second stand 3 is maintained in the state immediately before the start of the work roll shift. Issue a command. That is, the first stand 2 and the second stand 3 are in operation during the work wheel shift.
The tension control between them is not performed.

Next, a cold rolling method for a plate material, in which a work wheel shift is performed during rolling, according to a fourth embodiment of the present invention will be described with reference to FIG.

FIG. 6 shows a cold rolling method for a plate material in which a work roll shift is performed during rolling according to a fourth embodiment of the present invention.
It is a control system diagram for explaining. 6, the same configuration as that described in FIGS. 1, 3 and 5 is the same as in FIGS.
The same reference numerals as 5 and 5 are given, and detailed description thereof is omitted. The cold rolling method of the plate material in which the work wheel shift is performed during rolling in this embodiment is performed by the work roll rolling during rolling.
1, 3 and 5 during steady rolling without the shift shift.
The tension control between the first and second stands is performed by the same method as described in 1. above. Then, when the work wheel 2a of the first stand 2 is axially shifted by the work wheel shift control device 7 during rolling, the work wheel shift control device 7 causes the work wheel roll 2a to shift. The le-shift start signal is sent to the tension control device 5 and the BISRA-AGC 10.
In the tension control device 5, the control command to the hydraulic pressure lowering device 6 of the second stand is stopped until the work wheel shift end signal is sent from the work wheel shift control device 7. At the same time, the BISRA-AGC 10 issues a command only to the hydraulic pressure reducing device 11 of the first stand 2 so that the roll gap of the work roll in the first stand 2 is kept constant.

Next, referring to FIG. 7, a cold rolling method for a plate material in which a work wheel shift is performed during rolling according to a fifth embodiment of the present invention will be described.

FIG. 7 shows a cold rolling method for a plate material in which a work wheel shift is performed during rolling according to a fifth embodiment of the present invention.
It is a control system diagram for explaining. 7, the same components as those described in FIGS. 1, 3, 5 and 6 are designated by the same reference numerals, and detailed description thereof will be omitted. In the cold rolling method of the plate material for performing the work roll shift during rolling of this embodiment, the work roll 2a of the first stand 2 is controlled by the work roll shift control device 7 during rolling. When shifting in the axial direction, a work wheel shift start signal is sent from the work wheel shift control device 7 to the tension control device 5. In the tension control device 5,
From the time when the work wheel shift start signal is received, the tension control by the hydraulic pressure reduction device 6 is stopped. And the work
While performing the chrome shift, the tension control device 5 is based on the tension signal from the tensiometer 4 and the work of the first stand 2 is operated.
The rotation speed of the drive motor 12 of the crawl 2a is changed to control the tension between the first and second stands until a work-roll shift end signal is input from the work-roll shift control device 7. To do. Then, after the end of the work wheel shift, the control returns to the tension control by the hydraulic pressure reduction device 6.

In the graph of FIG. 8, when the work roll shift is performed at the first stand, the tension control is performed during the steady rolling without the work roll shift during the rolling, and the hydraulic pressure reduction device 6 of the second stand 3 is used. The work roll shift is performed from the start to the end, and the work roll 2a of the first stand 2 is used.
FIG. 7 (a) shows the changes over time in the plate thickness and tension when the rotational speed of the drive motor 12 of FIG.
Is the work roll shift position of the upper and lower work rolls of the first stand for performing work roll shift, and (b) is the change in the rotation speed with reference to the work roll rotation speed during steady rolling. Rate, (c) is the thickness deviation on the exit side of the first stand,
(D) shows the thickness deviation on the delivery side of the second stand, (e)
Shows the plate thickness deviation on the exit side of the fifth stand, which is the final stand, and (f) shows the change in tension between the first and second stands. As shown in FIG. 8 (f), the tension fluctuation between the first and second stands is smaller than that in the conventional method, and the decrease in the second stand outlet side plate thickness is as shown in FIG.
It is suppressed as shown in (d), and the plate thickness variation in the final stand is also reduced to a level at which there is no practical problem as shown in FIG. 8 (e).

[0057]

According to the present invention, since the parameters and the control method relating to the tension control are changed from the start to the end of the work roll shift, it is possible to prevent the plate thickness variation and to stably stabilize the cold tandem. Rolling can be performed.

[Brief description of drawings]

FIG. 1 is a control system diagram for explaining a cold rolling method for a plate material that performs a work roll shift during rolling according to a first embodiment of the present invention.

FIG. 2 is a graph showing changes over time in plate thickness and tension when a cold rolling method for a plate material in which a work roll shift is performed during rolling according to the first embodiment of the present invention is carried out, (A)
Is the work roll shift position of the upper and lower work rolls of the first stand for performing the work roll shift, (b) is the band width in tension control, and (c) is the plate thickness on the delivery side of the first stand. Deviation, (d) is the thickness deviation on the outlet side of the second stand, (e) is the thickness deviation on the outlet side of the fifth stand, which is the final stand, and (f) is the change in tension between the first and second stands. Are shown respectively.

FIG. 3 is a control system diagram for explaining a cold rolling method for a plate material which performs a work roll shift during rolling according to a second embodiment of the present invention.

FIG. 4 is a graph showing variations with time of plate thickness and tension when a cold rolling method for a plate material in which a work roll shift is performed during rolling according to a second embodiment of the present invention is carried out; (A)
Is the work roll shift position of the upper and lower work rolls of the first stand for performing the work roll shift, and (b) is the change amount of the target value based on the target value of the tension control during steady rolling.
(C) shows the thickness deviation on the delivery side of the first stand, (d)
Is the thickness deviation on the delivery side of the second stand, and (e) is the thickness deviation on the delivery side of the fifth stand, which is the final stand.
(F) shows changes in tension between the first and second stands.

FIG. 5 is a control system diagram for explaining a cold rolling method for a plate material, which performs a work wheel shift during rolling according to a third embodiment of the present invention.

[Fig. 6] Fig. 6 is a control system diagram for explaining a cold rolling method for a plate material in which a work roll shift is performed during rolling according to a fourth embodiment of the present invention.

FIG. 7 is a control system diagram for explaining a cold rolling method for a plate material which performs a work roll shift during rolling according to a fifth embodiment of the present invention.

FIG. 8 is a graph showing changes over time in plate thickness and tension when a cold rolling method for plate materials in which a work roll shift is performed during rolling according to a fifth embodiment of the present invention is carried out; (A)
Is the work roll shift position of the upper and lower work rolls of the first stand for performing work roll shift, and (b) is the change in the rotation speed with reference to the work roll rotation speed during steady rolling. Rate, (c) is the thickness deviation on the exit side of the first stand,
(D) shows the thickness deviation on the delivery side of the second stand, (e)
Shows the plate thickness deviation on the exit side of the fifth stand, which is the final stand, and (f) shows the change in tension between the first and second stands.

FIG. 9 is a graph showing changes over time in rolling load and plate thickness when a cold rolling method for a plate material in which a work wheel shift is performed during conventional rolling is performed, and FIG. -Upper and lower walkers on the first stand for shift shifting
The shift position, (b) the fluctuation of the rolling load on the first stand, (c) the change of the plate thickness on the outlet side of the first stand, (d) the change of the plate thickness on the outlet side of the second stand, (E) is a graph showing a change in plate thickness on the exit side of the fifth stand, which is the final stand.

FIG. 10 is a graph showing changes over time in the advance rate and tension in the case of performing a cold rolling method for a plate material in which a work wheel shift is performed during conventional rolling, and (a) is a work roll (B) is the first
2 is a graph showing a change in tension between two stands, and (c) is a graph showing a change in tension on the first stand entry side.

[Explanation of symbols]

1 plate material 2 First stand 2a work roll 3 second stand 3a Work roll 4 Tensiometer 5 Tension control device 6 Hydraulic pressure reduction device for the 2nd stand 7 Work roll shift control device 8 Rolling position control device 9 calculator 10 BISRA-AGC 11 Hydraulic pressure reduction device for the first stand 12 Drive motor for 1st stand wheel

─────────────────────────────────────────────────── ─── Continuation of the front page (56) Reference JP 62-227503 (JP, A) JP 7-100502 (JP, A) JP 61-126904 (JP, A) JP 5- 177227 (JP, A) JP 5-31517 (JP, A) JP 3-47613 (JP, A) (58) Fields investigated (Int.Cl. ⁷ , DB name) B21B 1/00-1 / 46 B21B 37/00-37/78

Claims (5)

(57) [Claims] 1. A stand capable of axially shifting work rolls arranged vertically opposite to each other, and the output side tension of the shifting stand is changed by changing the roll gap of the next stand. In a cold rolling method for a plate material, in which a work roll shift is performed during rolling, using a continuous cold rolling mill equipped with a tension control means for controlling, a shift from the start to the end of the work roll shift is performed. The work roll shift during rolling is characterized in that the band width of the tension control means for controlling the exit side tension of the stand is set to be larger than the band width during steady rolling without performing the work roll shift. Method for cold rolling a plate material. 2. A stand capable of axially shifting a work wheel arranged vertically opposite to each other, and changing the output side tension of the shifting stand to the roll gap of the next stand. In a cold rolling method for a plate material, in which a work roll shift is performed during rolling, using a continuous cold rolling mill equipped with a tension control means for controlling, a shift from the start to the end of the work roll shift is performed. The target value of the tension control of the tension control means for controlling the exit side tension of the stand is set to be higher than that in the steady rolling without performing the work roll shift, and the work roll shift is performed during the rolling. A method of cold rolling a plate material. 3. A vertically displaceable work wheel is controlled by a stand capable of shifting in the respective axial directions, and the output side tension of this stand is controlled by changing the roll gap of the next stand. In a cold rolling method for a plate material, in which a work roll is shifted during rolling, a continuous cold rolling mill equipped with a tension control means for Rolling is performed while the roll gap of the next stand is not kept constant from the start to the end of roll shift, and during steady rolling without work roll shift, rolling is performed while being performed by the roll gap control means. A method of cold rolling a plate material in which work roll shifting is performed. 4. A stand capable of vertically shifting the work wheels arranged in the respective axial directions, and the output side tension of the shifting stand is changed by changing the roll gap of the next stand. Using a continuous cold rolling mill equipped with a tension control means for controlling and a BISRA type plate thickness controlling means for controlling the roll gap in the shiftable stand, a sheet material for performing work roll shift during rolling is used. In the cold rolling method, the exit side tension of the shifted stand is controlled by adjusting the roll gap of the shifted stand from the start to the end of the work wheel shift.
Cold rolling of a plate material subjected to work roll shift during rolling, which is performed by SRA type plate thickness control means, and during steady rolling without work roll shift, rolling is performed while being performed by the tension control means. Method. 5. A continuous cold machine equipped with a stand capable of vertically shifting the work wheels arranged in the respective axial directions and a tensiometer arranged on the outlet side of the shifted stand. In a cold rolling method for a plate material in which a work roll is shifted during rolling by using a rolling mill, the output side tension of the shifted stand is controlled by the shifted stand from the start to the end of the work wheel shift. Rolling is performed by changing the rotation speed of the work roll, and during steady rolling without performing work roll shift, rolling is performed by changing the roll gap of the next stand based on the tension signal from the tensiometer. A method of cold rolling a plate material, which comprises performing work roll shift during rolling.